Copper catalysed [3+2] cycloaddition with concomitant annulation: formation of 2,4-diaryl-1,4-oxazepan-7-ones via a ketenimine route

A novel strategy for a copper catalyzed cascade reaction involving intramolecular nucleophilic addition to N-sulfonylketenimine gratifyingly furnishing 1,4-diaryl oxazepan-7-one has been described.